Expansible lifting-arm.



R. D. TYLER.

EXPANSIBLE LIFTING ARM.

APPLICATION FILED FEB. 10. 1916.

1,1 QUAW. Patented M 11, 1916.

. I J i BOY D. TYLER, OF CHICAGO, ILLINOIS, ASSIGNOR TO JOHN C.

MONINGER COMPANY, OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

EXPANSIBLE LIFTING-ARM.

ILJQOASG.

Application filed February 10, 1916.

To all whom it may concern.

Be it known that I, Roy D. TYLER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Expansible Lifting- Arms, of which the following is a specification.

My invention relates to lifting arms that are capable of longitudinal extension and which occupy relatively small space, when contracted, for lifting one end of a hinge sash or other closure.

One of the general objects of my invention is to provide an expandible lifting arm, especially designed for lifting sash in green houses, which will lie very close to the sash when contracted to permit maximum headroom within the house, which maybe ex tended and contracted by rotation of a shaft, to which a plurality of such arms may be attached, and which is capable of maximum extension upon the slight rotation of the shaft.

More specific objects of my invention are to provide an improved joint between the hinged members of the arm to prevent rusting and consequent resistance by tightening up of the joints; to place the entire device on one side of the operating shaft; to pro vide a stop on the shaft, to prevent excessive movement of the shaft when the arm is being contracted; to offset the hub carrying the expanding arm members so that the members thereof may lie closer to the shaft when contracted, thereby to occupy smaller space; to connect the terminals of the arm,

' to a shaft bracket which projects from one side of the shaft, and in such manner that the links or members of the respective series will at all times be in substantial parallel planes to each other, and to generally improve devices of this character.

Other and further objects of my invention will become readily apparent, to persons skilled in the art, from a consideration of the following description when taken in conjunction with the drawings, wherein Figure 1 is an elevation of my device when contracted, showing a shaft and sash, between which it extends, in cross section and showing the sash and arm in closed positions. Fig. 2 is a similar view, showing the arm fully extended, and the sash fully open. Fig. 3 is an enlarged transverse sec- Specification of Letters Patent.

Patented July 11, 1916.

Serial No. 77,476.

tional view, taken on line 33 of Fig. 1. Fig. l is an enlarged transverse section taken on line &4 of Fig. 2.

In all the views the same reference characters are employed to indicate similar parts.

5 is the sash which may form a closure for a green-house; for a ventilating window, or the like, which is adapted to be moved upon its hinged end, not shown in the drawing, from the closed position, shown in Fig. 1, to the wide open position shown in Fig. 2. In some green-houses, head room under the sash is very desirable and therefore it is of in'iportance that the lifting arm should occupy as small space as consistent, thereby to prevent as little contraction of the head room as possible.

In the specific embodiment 6 is a rotatable shaft upon which a number of extension arms 7 may be secured for as many different windows or other closures. The arm is composed of a number of centrally pivoted links or members. In the particular en'ibodiment 8, 9 and 10 are relatively long members loosely pivoted together, as at 11. and 12, respectively. Members or links 13 and 11 are pivoted together, as at 15; the link 13 being pivoted to a relatively short link 16, as at 17, and the link 1 f being pivoted to a relatively short link 18, as at 19. Secured to the shaft is a two part bracket 20, consisting of an arm and an offset hub 21 providing a clamping member 22 for underlying the shaft, secured to the integral cooperating hub member 23, by bolts 24 which pass through laterally extending ears 25 and 26, in the respective hub members, to clamp the fixture 20 to the shaft. The upper part, or hub member 23, is provided with an integral laterally extending arm 28 having a rib 29 on one side and ears 30 and 31 on the other side of a central space. The inside surface of the rib 29 is in the same transverse plane as the adjacent transverse surface of the hub 21, so that the link may pass the hub and rest upon the shaft, when the arm is fully contracted, as shown in Fig. 1.

The link 10 carries upon its extended end a clip 32, to which it is pivoted, as at 33. This link is also pivoted to the link 18, as at 34. .In Fig. l I have shown the manner of riveting the link members together to prevent corrosion, or oxidation, and so that the link members will always operate with a minimum frictional resistance. I provide a rivet 35, having on one end a relatively large head 36, and having a relatively large shank 37, which is longer than the thickness of one link member, and which extends through and beyond an intermediate washer 38, and into contact with the opposite link member. The shank 37 is sufliciently long to permit some latitude of movement of the washer 38. The rivet is also provided with a smaller shank 39 which extends through the adjacent link member and is headed over, as at 40. The washer 38, is preferably made of some material, such as Babbitt metal, brass, or the like, when the link members are to be made of iron or steel. The composite arm is entirely extended, as shown in Fig. 2, when the bracket 20 is rotated from a horizontal plane to an angularposition about 22 degrees vertically removed from the horizontal plane, and it is entirely and completely contracted when the bracket 20 is returned to its horizontal postion. Any further rotation of the shaft 6, to the left, as shown in Fig. 1, will cause the link 16 to rest upon the upper surface of the shaft, which serves as a lock, to prevent any further movement in that direction, and to protect the device against unnecessary strain. 7

Having described my invention, what I claim is:

1. A sash arm adapted to be extended and contracted by oscillation of a shaft, comprising two series of pivoted together link members, one series on each side of the longitudinal median plane, the central portion of crossing links of the respective series pivoted together; a bracket, for extension from one side of a shaft and positioned to lie at all times above a horizontal plane passing through the axis of the shaft, said bracket having terminal links of each series pivoted thereto so as to lie in parallel planes and means to secure the bracket to a shaft.

2. A sash arm adapted to be extended and contracted by oscillation of a shaft, comprising two series of pivoted together link members, one series on each side of the longitudinal median plane, the central portions of crossing links pivoted together; a bracket arm, for lateral extension from one side of the shaft and positioned to lie at all times above a horizontal plane passing through the axis of the shaft, said bracket having terminal links of each series pivoted thereto so as to permit the attached links to lie in parallel planes, and an integral hub and headed beyond the other link member.

In testimony whereof I hereunto set my hand in the presence of two subscribing witnesses.

Fomin BAIN, MARY F. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner vof Iatents, Washington, D. C. 

